Coastal Coastal Marine Marine EcologyEcologyFrom RiversFrom Rivers

To Reefs…To Reefs…

What is anWhat is an ESTUARY?...ESTUARY?... A semi-enclosed A semi-enclosed coastal embayment coastal embayment where fresh and where fresh and saltwater meet and saltwater meet and mix (brackish).mix (brackish).

In contrast to other In contrast to other transitional eco-transitional eco-systems, estuaries systems, estuaries have few species of have few species of permanent permanent residents.residents.

Types of Types of EstuariesEstuaries…… COASTAL PLAINCOASTAL PLAIN: : the most the most

commoncommon Formed at the end of the last Formed at the end of the last

ice-age due to rising sea level.ice-age due to rising sea level.

ExampleExample: Chesapeake Bay: Chesapeake Baythe largest in the United the largest in the United States.States.

Semi-enclosed bay or Semi-enclosed bay or lagoonlagoon Sandbars build up parallel to the Sandbars build up parallel to the

coastline and partially cut off waters coastline and partially cut off waters behind them from the sea.behind them from the sea.

This creates a This creates a shallow shallow lagoon behind lagoon behind the sandbars, the sandbars, which collects which collects runoff.runoff.

Example of a lagoon Example of a lagoon estuary:estuary:

Pamlico Sound off Cape Hatteras, NC. The narrow band of barrier islands forms the lagoon.

Physical Physical Characteristics of Characteristics of Estuaries:Estuaries:

Conditions in estuaries vary a lot, which can Conditions in estuaries vary a lot, which can create a stressful environment for organisms:create a stressful environment for organisms:

SalinitySalinity-- the dominant factor of the the dominant factor of the estuarine environment is the estuarine environment is the fluctuation in salinity.fluctuation in salinity.- the major factor affecting salinity is - the major factor affecting salinity is runoffrunoff from the surrounding from the surrounding watershed.watershed.- when salinity is greatest at the - when salinity is greatest at the bottom and lowest near the surface, a bottom and lowest near the surface, a salt wedgesalt wedge forms. forms.

SalinitySalinity Adaptations…Adaptations… To survive, benthic To survive, benthic

organisms must be organisms must be able to tolerate able to tolerate frequent changes frequent changes in salinity.in salinity.

The great majority The great majority of estuarine of estuarine animals are marine animals are marine species.species.

Oysters stop Oysters stop feeding & close feeding & close their shells when their shells when salinity goes down.salinity goes down.

Others burrow.Others burrow.

Salt Marsh Salt Marsh EstuariesEstuaries……

Salt marshes border temperate (4Salt marshes border temperate (4 seasonal changes) and sub-polar seasonal changes) and sub-polar estuaries and protected marine shores estuaries and protected marine shores worldwide.worldwide.

Form a Form a transition areatransition area between aquatic between aquatic and terrestrial (land) ecosystems.and terrestrial (land) ecosystems.

Communities of emergent Communities of emergent plants (plants that stick up plants (plants that stick up out of the water), known as out of the water), known as HALOPHYTESHALOPHYTES, rooted in , rooted in soils alternately flooded & soils alternately flooded & drained by tidal action.drained by tidal action.

Salt marshes act as Salt marshes act as “kidneys” to filter water, “kidneys” to filter water, “sponges” to absorb high “sponges” to absorb high waters during storms, and waters during storms, and “nurseries” for many “nurseries” for many valuable marine species.valuable marine species.

Life cycle of the edible pink shrimp:

Barrier IslandsBarrier Islands:: A string of sand isles A string of sand isles

that runs parallel to that runs parallel to the Atlantic & Gulf the Atlantic & Gulf coasts.coasts.

So called because So called because they protect the they protect the mainland from mainland from storms.storms.

295 major islands in 295 major islands in the 18 coastal states the 18 coastal states from Maine to Texas.from Maine to Texas.

Florida is 1Florida is 1stst with 80, with 80, followed by SC w/35.followed by SC w/35.

Barrier Islands:Barrier Islands: Bordered on one Bordered on one side by tidal side by tidal marshes, creeks marshes, creeks & rivers, and on & rivers, and on the other side the other side by beaches, by beaches, sand dunes, sand dunes, sand bars.sand bars.

Between lies the Between lies the maritime forest, maritime forest, made up made up primarily of oaks primarily of oaks and palm trees.and palm trees.

Cross-section of a typical barrier Cross-section of a typical barrier islandisland

Ocean Ocean Swash zoneSwash zone

Primary Primary dunesdunes

Secondary dunesSecondary dunes

Barrier Barrier flatflat

Maritime forestMaritime forest

Salt Salt marshesmarshes

BayBay

Cross section of a salt Cross section of a salt marshmarsh

Tidal creekTidal creek Maritime forestMaritime forest

SpartinaSpartina Black needle rushBlack needle rush

Tidal creekTidal creek

Flora & Fauna of theFlora & Fauna of the Salt Salt MarshMarsh

PlantsPlants::salt marshes are one of the most salt marshes are one of the most productive ecosystems on Earth, along productive ecosystems on Earth, along with rain forests, sea grass beds, kelp with rain forests, sea grass beds, kelp forests and sugarcane fields.forests and sugarcane fields.

Salt marshes are so productive Salt marshes are so productive because of the abundance of the salt because of the abundance of the salt marsh cordgrass called marsh cordgrass called SpartinaSpartina..

Also present are plants called black Also present are plants called black needle rush, and salt pickle.needle rush, and salt pickle.

Salt marshSalt marsh cordgrasscordgrass SpartinaSpartina

Spartina Spartina grows grows the closest to the the closest to the banks of the tidal banks of the tidal creeks that creeks that wander through wander through the marsh.the marsh.

It is a perennial It is a perennial plant that, as it plant that, as it dies off, produces dies off, produces huge amounts of huge amounts of detritusdetritus, that is , that is used for food.used for food.

““Where in the marsh are Where in the marsh are we???”we???”

Spartina (cord grass)

Salicornia (pickle weed) Juncus

(black needle rush)

Animals of the SaltAnimals of the Salt Marsh…Marsh… The most abundant animal is the The most abundant animal is the fiddler fiddler crab (crab (Uca pugilatorUca pugilator).).

As As detritovoresdetritovores, they are an important link , they are an important link in the food chain.in the food chain.

Males have one large claw.Males have one large claw.

Fiddler crab burrows aerate Fiddler crab burrows aerate the mud which affects the mud which affects SpartinaSpartina growth. growth.

Grass shrimp:Grass shrimp: Abundant along Abundant along

both Atlantic and both Atlantic and Gulf coasts.Gulf coasts.

Also an important Also an important link in the link in the estuary/salt marsh estuary/salt marsh food web.food web.

Detritovores.Detritovores. Can be collected Can be collected

at high tide along at high tide along grass line.grass line.

Birds of the Salt Birds of the Salt Marsh…Marsh… Rarely does one visit Rarely does one visit

the salt marsh that a the salt marsh that a number of different number of different birds can’t be seen.birds can’t be seen.

Great blue heronGreat blue heron PelicanPelican Sea gullSea gull Black skimmerBlack skimmer Clapper railClapper rail

Mangrove Mangrove Swamps…Swamps…

A type of tree A type of tree that replaces that replaces salt marshes.salt marshes.

Found in warmer Found in warmer tropical/sub-tropical/sub-tropical tropical environments.environments.

4 types4 types::red, black, white red, black, white and buttonwood.and buttonwood.

The most The most obvious is the obvious is the red man-grove red man-grove because of its because of its “prop roots.”“prop roots.”

Red Red Mangorves:Mangorves:

““The tree that walks.”The tree that walks.” Red mangroves Red mangroves

produce seedlings produce seedlings called “propagules” called “propagules” that drop from the that drop from the tree and either take tree and either take root where they fall, root where they fall, or drift away on the or drift away on the tide.tide.

As they grow, they As they grow, they build up more land as build up more land as the roots trap the roots trap sediment that sediment that otherwise would have otherwise would have choked out coral choked out coral reefs.reefs.

Ecosystem from top to Ecosystem from top to bottom!bottom!

One of Florida’s One of Florida’s true natives.true natives.

Able to Able to separate fresh separate fresh water from salt water from salt water.water.

Their roots Their roots provide nursery provide nursery grounds for grounds for many marine many marine species.species.

Canopy Canopy provides provides rookeries for rookeries for pelicans, etc…pelicans, etc…

BlackBlack Mangroves:Mangroves: Found growing higher Found growing higher

up above the reach of up above the reach of high tide than the red high tide than the red mangrove.mangrove.

Are more salt tolerant Are more salt tolerant than the red even than the red even though it is further though it is further out of the water.out of the water.

Has distinctive roots Has distinctive roots sticking up out of the sticking up out of the mud called mud called “pneumatophores.”“pneumatophores.”

Beaches & Beaches & Dunes:Dunes: